As a conventional speaker apparatus for performing reproduction while achieving the directionality in the reproduction direction of an audio signal, a tonzoile type speaker apparatus is generally known, for example. In the tonzoile type speaker apparatus, a plurality of speakers (or speaker units) are aligned in a lateral direction (i.e. horizontal direction) and separated by a predetermined distance. Of them, if attention is focused on two speakers disposed and separated by the predetermined distance, the audio signals reproduced from the two speakers are canceled because of a phase difference caused by the predetermined distance, with regard to sound waves emitted in the lateral direction, in a frequency corresponding to a wavelength twice as long as the predetermined distance. Incidentally, in a front direction, the audio signals reproduced from the two speakers are combined, and a sound pressure level increases. Thus, it is generally known that there is a significant difference in sound level, between the sound pressure level in the front direction and the sound pressure level in the lateral direction. Moreover, in a patent document 1 and the like, such methods are suggested that the tonzoile type speaker apparatus is developed.    Patent document 1: Japanese Patent Publication NO. 2528178    Patent document 2: Japanese Patent Publication NO. 2675388    Patent document 3: Japanese Patent Publication NO. 2846363    Patent document 4: Japanese Patent Publication NO. 3473517    Patent document 5: Japanese Patent Publication NO. 3422281    Patent document 6: Japanese Patent Publication NO. 3422282    Patent document 7: Japanese Patent Publication NO. 3422296    Patent document 8: Japanese Patent Publication NO. 3205625    Patent document 9: Japanese Patent Publication NO. 2574454